Process of smelting ores.



No. 891,630. I PATENTEDLJUNBIZS, 190

- E. L. MGGAHAN- PROCESS, OF SM'ELTING REs.

APPLICATION FILED JUNE 28 1905.

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. mi k/war: Fred L. McGahan I dram/5rd No'. 891,630. 1 I I PATENTED JUNE 23, 1908.

.P. L. MOGAHAN.

PROCESS OF SMBLTING ORE S.

APPLICATION FILED JUNE 28,1905.

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wlmsssss Fr d L. McGa han.

PATENTED JUNE 23', 1908 P; L. McGAHAN. PROCESS OF SMELTING ORES APPLICATION FILED JUNE 28, 1906.

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INVENTOI? I Fred L. McG-ahan.

FREDERICK L. MCGAHAN, OF ST. LOUIS, MISSOURI.

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Specification ofLetters Patent.

Patented June 23, 1908. I;

Applicationfiled 'J'une2 8, 1905. Se1-iii1No.267,400.

To all whom tftmay comer n." Be it known that 1, F-nEnnmc-K L. Mo- GAHAN', a citizen of the "United States, re-

siding at the'city of St. =Louis,' State of Mis:

sour'i, have invented a certain new and useful Process of smelting Ore, of which the fol.

lowing such a full, clear, and exact descriptlon as will enable any one skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification. J a

My invention relates to smelting of ores, and more particularly to a process in which certain unconsumed gases and roductsof combustion from the smeltin urnace are .not discharged into the admixture in theusual manner, but after being suitably treated are returned to the furnace.

- One important feature of my process is that I employ successively a number of different temperatures, each higher than the one before, so as to separate various metals and metallic-substances'oneat a time from ores containing more than'one metal.

By returning the products of combustion and unconsumed ases-I prevent the loss of a heat and fuel, an also retain such volatilized metallic substances as would otherwise result from their discharge into the admixtu're. The products of combustion from the I furnace, wh1lecontaining a certain amount of fuel do not, as a rule,-con-tain suflicient fuel to carry on the process of smelting, hence I add to said roducts after they are withdrawnfrom an before they are again returned tothe furnace, other fuel, either in a powdered or-liquid-form. 'I also add to saidproducts of. combustion a certain amount of steam, which, during the process, is decomposed igrtoits constituent elements. In this manner *I am enabled to supply suflicient fuel and oxygen to the furnace to carry on the process of smelting without admitting any, or at least only a very small amount, of

atmospheric air to the furnace; consequently during the fullolperation of the furnace it contains but litte or no nitrogen; I'find that has an important bearing u on the chemical redetionsstaking place wit 'n the fum'ace'and enables me to obtain substantially. the same-results thata're obtained in the electric smelting furnace.

The construct-ionof the furnace by means of which I prefer to carry on my process, brieflystated is as follows: Iprovide a pair smelting chamber is also an inclined inclosure divided by a grating into a roasting chamber being provided with a fuel injector for injecting fuel in order to heat the main or smelting chambers. Leading from each chamber and a circ ating chamber. two inclined inclosures are connected at their" upper, ends and at this point is attached a pipe through which the heated products of combustion and gases are drawn ofi over the ore in the roasting chamber by means of a suction fan. The said gases and products of combustion are then delivered to a car- .bureter inwhichthey are enriched by the addition of any suitable fuel, either liquid or pulverized, after which the said gases and products of combustion are again returned. to the smelter roper by means of a second suction fan. efore being returned to the furnace proper the gases are first passed through super-heating pipes arranged adjacent to the smelting c ambers and are chambers hereinbefore referred to! .then delivered to the various combustion ing drawings forming apart of this spec cation, in which similar characters of reference. indicate corresponding, parts in all the tion on an enlarged scale through the smelter ticul-arly in connection wit the form of fur proper; Fig. 4 is an enlargedcross section 5 through F1g. "6; Fig. 5.is a' vertical section through the smoke box of a boiler showing the'superheat'ing coil '88 for raising the temperature of the gaseous products 0 comb'us tion after the carbureting thereof;-Fig. 6 isga. top plan view, partly in section, of the parts shown in Fig.3; and Figs' 7 and 8 are ver-' tical sections through the cavbmeter, 8

being taken on a section in'Fig. 7.

I will now describe my rocess more par:

line at light angles-to the nace by means of which I prefer to carry it on in practice.

At 10. are the two smelting chambers, Which are preferably cylindrical and upright in form. --Opening laterally off these smelt- Reference is to be had to-the accompang: 5

set

ing chambers are the combustion chambers 11, which are preferably arranged at an angle of about 45 with-the said main or Each of these co1n-' smelting chambers 10. bustion chambers 11 is provided with a fuel injector 12, which is provided with a supply of fuel and steam by pi e connections, which will be hereafter descri ed.

13 are inclined inclosures, preferably arranged at an angle of about 45. Each of these inclosuresvis divided by means of a grating of water tubes 14 into an upper or roasting chamber 15 and a lower or circulating chamber 16. The ends of the pipes 14 are secured in boxes 17, which in turn are connected by means of pipes 18 and 19 with water drums 20 arranged at each side of and slightly above the said inclined inclosures 13.

The roasting chambers 15 are separated from the smelting chambers 10 by means of being smelted in the smelting furnaces 10.

The upper end of each of the roasting chambers 1.5 is provided with a swinging door 26, so that the upper end of the said chambers can be opened for the insertion of the charge of ore; Such charge of ore is preferably inserted by means of a hopper 27 which is provided with a slide 28 and a telescopic portion 29. The said telescopic portion 29 is adapted to be lowered into the position shown in Fig. 3, so that when the slide 28 is drawn the contents of the hopper 27 will be discharged into the roasting chamber 15. Leading from the point of junction of the two circulating chambers 16 is a pipe 32 through which the heated products of combustion and un-consumed gases are drawn off by means of a fan 33'. These gases and products of combustion are then discharged into a carbureter 34, as shown in. detail in Figs. 7

and 8. The pipe 32 leading from the fan 33. has an enlarged end 35 which passes down through the carbureter 34, and is preferably slightly belled at the end, as shownvat Opening into'the enlarged portion 35 is a second pipe 37, which leads from the smoke stack of the boiler 38. The fan 39 is provided for drawing off the products of combustion and heated gases from the boiler 38 I through the pipe 37 and discharging them into the lower enlarged end 35 of the pipe 32 Arran ed just above this crucible 40 is a perforated diaphragm-41 .and above said diaphragm 41 is an imperforate' diaphragm 42.

Passing through these two diaphragms 41 and 42 are a plurality of ipes 43, preferably made of two different fengths as clearly shown in the drawings. 4 These pipes are arranged annularly in close proximity to the outer shell of the carbureter 34, and their object is to allow the passage of oil or oil and water through the space separated by the diaphragms 41 and 42. .This construction enables the carbureter to perform the functions of a jet condenser, thus assisting the draft of the furnace, as hereinafter more fully described. Between the diaphragms 41 and 42 and closely surrounding the p pes 35 is a gas generating chamber 45. 'Leading from this gas generating chamber 45 are a pair of pipes 46 which are connected to a suction fan 47. Leading from the fan 47 are a pair of pipes 48 which return the gases and heated products of combustion to the smelter proper. Leading from the carbureter 34 below the crucible 49 are a pair of pipes 50. which are, in turn, connected to separating tanks 51. Below each of-the separating tanks 51 is ar-- ranged a'dead oil tank 52 with which it is connected by means of pipes 53. Leading from the two dead oil tanks 52 is a pipe754 which is connected by means of a pipe 55 with a pump 56. Leading from the pump 56 is a pipe 57 through which the dead oil from the tanks 52 is pumped into a reservoir 58. 59 is a return pipe fromthe reservoirv 58, through which the dead oil is returned to the carbureter 34.

In order to prevent the carbureter from falling to too low a tem erature, Iprefer to provide it with a pair 0 burners 60. These burners 60 are each rovided with an oil pipe 6]. by means of which the oil is supplied tot-he burner. These pipes 61 are connected to a pipe 62 which leads from a pipe 63 communi' eating with the fuel oil tank 64. The pipe 62 is also connected with the burner boiler 38.

In order to heat the fuel oil in the tank 64 I provide a steam coil 66 in said tank. This coil 66 is supplied by steam from a lpipe 67, whichis connected by a pipe 68 wit a pipe 69. The said pipe 69 is connected to the steam drum 70 of the boiler 38. The pipe 67 is connected to the steam cylinder of the steam pump 56 hereinbefore-referred ,to and also to the steam cylinder of a second pump 72. The exhaust of the steam cylindersfrom both the pumps 56 and the purnp 72-passes through a pipe 73 to the carbureter 34. The suction end of the pump cylinder of the pump 72 is connected by means of a pipe 74 with a retort 75 connected with the gas generating chamber 45 of the carbureter 34 and the said suction end of the said cylinder is also con-. nected by means of a. pipe 76 'iivith a series of separating chambers 77 in a passage 78 leading to a well 79. The passage 78 receives the discharge from a rel ef pipe 60 extending 65 of the 891,630 I at from the pipe 32. It also receives the dischargefrom a relief pipe81. The ipe. 81 is connected w' the separating tan 51 and als'othrough a pipe 82 ,withthe pipe )7 a d the pipes 46; 831's the discharge pipe from a 1 thel'pump cylinder of the-pump '72. I This pipjel83 may lead-t0 any suitable receptacle of illevarious products withdrawn from the carbureter 34 and theseparating chamber 7 7 The carbureter :34 also receives the exhaust from 'the heati1ig coil 66 in the fuel oil tank 64. -This exhaust passes from the coil 66 through 9. ie 85 passing along within the pipe 63. aust steamis also supplied to 5 .5 the carbureter 34 through a. pipe 86 leadingfi'o'm theengine 87. At the same time that flxlmustfsteam'is suppliedto the carbureter thr the ipe 86, water and dead oils-are supp ed tot e carbureter through a pipe 59,

thus'causin the carbureter to perform the functions 0% a -jet condenser, taking back pressure oil both the engine and fans and as? sistmg'the draft of-the furnace as well as rotecting the outer shell of the carbureter. he

251 engihe 87 is used to drive the various exhaust fans means of suitable counter-shafting and,b ting, which are not shown in thedraw- The engine 87 is supplied. with steam by means of the ipe 69 hereinbefore de 39 scribed. Leading om the steam dome 70'0f the boiler 38 is a pipe 87. The pipe 87 is connected with a super-heatin coil 88 ar- 'ifanged in thesmoke box ofit e boiler, as-

1 clearly shown in F' 5 of the drawing. Con- 5 nected with the coi '88 is a pipe 89, which is intuln connected to the pipe connections 90 Bhrl'mmding the two smelting chambers 10.

Leading from the pipe connections 90 to each of thefuel injectors 12-is a brarichconnec- V tion 91.

92 are oil-pipe connections also surrounding thesmeltmg chambers 10. Leading from these oil .pipe-connections'92 to each of the burners 12 IS a branch pi e '93. The oil pipe connections 92 are sup d, by means of a pipe 94 leading from gpipe 88, 95 are s'uper-heatingpipes whiolifare' arranged adjaoent to the smelting chambers 10. 1' These super-heating pipes 95 are' elerably four in number for each smeltin c amber, and they -are arranged'as cleaiYlys own in Fig. 6,so as to form a continuous,'one end of each ofsaid passfies being eonnected to one of the pi es 48 lea ing from the carbureter. Jeadi from one end of each ofthe superheati'ng pipes 95 is a branch pipe 97, which eads into one of the combustion chambers 1, so as to discharge the super-heated gases into said combustion chamber. Leading so into the opposite 'end of each of said superheati pipes,-95 is a branch pipe 98 leading from ,e-stearn' pipe connections 90. The dischar e nozzle 96 is also preferably provided with asupply pipe 99 leading-from'the as oil pipe connections 92. In order to sl pply pressure onthe fuel in the fuel ta'nk 64, I connect to said tank an air pip'e.101 leading from an air'pump 102. 1 This pump 102 also con- .nects with an'air tank 103 so that the supply of air maybe retained on hand after the plant is shut down in order to readily start the plant 'into operation. Leading from "the tank 102 and tank 103,are two pipes 104 and of the boiler 38'hereinbefore described and starting up the plant, or if desired at any other time,-compressed air may be used in the steam pi e connections 90in place of steam. In a dition to the liquid fuel fed to D the carbureter 381 may also provide a-hopper 110, as shown i-n"Figs-. 2 and 8 for receiving pulverized fuel, which may be fed into the crucible 40 .by means of a'screw 111. Ar,- ranged preferably belowthe discharge 112 from the hopperg 10 is a pi 113 leading from thecrucible 40 and provid d with an opening 114. Through this opening the gas within the carbureter 34 may be tested to discover 'be drawn ofi through the pipe 46 and sup; plied tothe smelting chambers. The pipes 59, 73, 85 and 86 are provided with valves means of these valves thesupplyof exhaust m from the carbureter are suipplied withj va ves 119 so that-the supply 0 gases from the carbureter tothe iurnace may be reguperature in the smelting furnace can be accurately' regulated, so that the furnace may be brought to and maintained at.any suitable degree of temperature. 'L'Thejtemperature of the furnace may be regulated b 'the valve alone. both'sets o valves, thus regulating not only the carbureting of the ases but also their return to the furnace.

bring the furnaceto and hold it at atemperature equal to the smelting point ofthe metal having the lowest smelting oint. 'The fur-- nace can -be retained at t is temperature until the furnace can be raised to the melting point of the metal having the next highest melting point and held at this temperature until the second metal is entirely removed from the 'ore and this process may be repeated With each metal until all are removed.

Asshown in the drawings, the valvesjlfi,

will be understood that they may be automaticall Y controlled by means of thermostats.

105. The pipe 104 leads to the burner 115, 116, 117 and 118, respectively. By

the.pipe 105 leads to the pipe 89 connected to the steam p'ipe connections so that:in

when it is of sufiicient richness to enable it to a steam, oil and water to the carbureter may be regulated, In like manner the pipes 45 lead- .latd. By means of these valves the tem-'- I 115, 116,117 or 11811110116, orbyt evalve 119 f In ractice, I prefer, however, to use ythis meansl am 1. enabled to treat ores containing"various .metals and to obtain each metal in asub stantially pure state, -In order todo-this I- 116, 117 and 118 are hand-operated, but it n practice it will be preferable to ob- 13'0 tain the regulation.automatically by means of thermostats. Inasmuch, however, as the use of thermostats for similar purposes is old and well-known, I have not deemed it necessary to show any specific form of thermostat in the drawings. v

It 'is possible that some unfused metals maybe alloyed to some extent with fused metals. The degree of such alloying, however, is very slight, the net result being that the metals of comparatively lower melting point may, when separated by my process, contain traces of other metals of slightly higher melting point. This is not particularly objectionable. As is well-known in this art the separation of lead from silver is readily brought about by cooling the admixture to such a point that it solidifies. The fact that the lead after separation contains traces of silver, and that the silver may contain more or less lead as an impurity, does not prevent the process from being operated successfully.-

So it is with my method; a slight admixture of one metal with an impurity in another may not be particularly objectionable, especially as the metals are sometimes afterward used for such purposes as would necessitate the admixture of more or less alloy therewith.

In carrying out my )rocess, ore is first placed in the smelting chambers 10, so that when the first charge of ore is smelted it has not been previously roasted. In all sueceedin charges, how-ever, the charge is roaster before being admitted to the smelt- In the regular operation of mitted from the roasting chamber 15 to the smelting chamber 10 by means of the movable gate 22, afterwl'iich a fresh charge of ore is placed in the chamber 15 to be roasted. The chamber 10 is heated by means of the combustion taking place not only in the said chamber itself, but also in'the combustion chambers 1 1 opening laterally from the main chamber. Fuel is suppliedthrough the pipe 96 and through the burners 12, and also through the pipes 97. The products of combustion containing any unconsumed combustible matter and also any metal which may have been volatilizcd in the smelting chamber is drawn off through the pipe 32 and thence carried to the carbureter 34, while in the carbureter 3 1 the various gases areenriched by means of fuel fed into the carbureter, as hereinbefore described, either in pulverizedor liquid form. After being enriched, the gases are returned to the pipes 46 and 48 to the super-heating pipes 95 surrounding the smelting chambers. 'In these pipes the gases are thoroughly super-heated and the steam contained in the gases decomposed to a greater or less extent into oxygen and hydrogen, after whlch the gases are fed to the furnace through the pipe 96,

and into the combustion chambers 11 the discharge pipes 107, I find that some of the metals are carried" over intothe carbureter 34 and can' be obtained from the said carbureter in the form of oxids or other.

chemical compounds. and Z1110 are contained 1n the ores a certain amountof lead would be deposited n the carbureter in the form of litharge in the proe--- ess of smelting the lead, and during the proc-' ess of smelting the zinc a certain amount of the zinc would be deposited in the said "car-j bureter in the form of zinc white. Other valuable by-products are also obtained from the carbureter through the retort 75.

' Since the point at which dissociation of the steam into oxy en and hydrogen does nottake place sud only, it may happen that when a part of the steam is dissociated such steam as does not become dissociated is simply exposed to a high degree of heat in contact with carbonaceous gpses and vapors, being thus caused to unite t erewith so as to form perfect ases which are afterwards carried into the furnace.

.Having'thu's described my invention, I claim as new anddesire to secure by- Letters Patent:

1. The process of smelting ore, which includes heating the ore in contact with a combustible, so asto liberate gases and other volatile product's, withdrawing said gases and other products, adding steam to' said gases and other products, subjecting the admixture to a temperature high enough to partially dissociate said steam, and returning the resulting aeriform body to the smelting zone of the furnace.

2. The process of smelting ore, 'whichineludes heating a charge of ore in contact with a combustible substance, so as to liberate gases and other Volatile products, withdrawing the latter and assing them over a'second charge of ore, ad ing steam to them, superheating them in contact with said steam, and returning the resulting aei iform bodyto the smelting zone of the furnace.

3. The recess of smelting ore, whichconsists in su jecting the ore to the action of a combustible body so as to liberate gases and other volatile products, withdrawing said gases and other volatile products,jcarburet- 1n the same, addingsteam to said gases and 0t er volatile products, subjecting the entire admixture to a temperature higher than that used in carbureting, and returning the resultfurnace. r

For instance, if lead I 4. The process of smelting ore, which includes subjecting the ore to the action of a combustible body, so as to liberate gases and other Volatile products, withdrawing said gases and volatile products, adding steam to them, superheating them and said steam to a temperature higher than that of either said gases or other products, or said steam, and

, returning the resulting aeriform body to the smelting zone of the furnace.

5. The process of smelting ore, which ineludes subjecting the ore to the action of a combustible body so as to liberate gases and other Volatile products, withdrawing said gases and other volatile products, passing. them over a second charge of ore, carbureting them, adding steam to them, raising the temperature of the admixture to a higher degree than that at which carbureting takes place, and returning said products to the smelting zone of the furnace.

6. The process of smelting ore, which in-, cludes heating said ore by aid of a combustibfesubstance so as to release gaseous products, carbureting said products, regulating the carbureting of said products with relation to the temperature, and returning said products to the smelting zone of the furnace.

7. The process of smelting ore, which i1 cludes heating a charge of ore in the presenr of a combustible substance so as to withdra the-gaseous and other volatile products, pas ing them over a second charge of ore, ca bureting said products, adding steam to sa products, preventing reduction of temper ture in said products after said steam added, returning said products to the sme? ing zone of the furnace, and regulating t: carbureting and return of said products maintain the ore at a predetermined tel perature.

8. The process herein described of sine ing ore, which includes heating a charge ore so as to withdraw therefrom the gasec volatile products, carbureting said produc raising steam by utilizing waste heat brii ing said steam intocontact with said pr( ucts, and finally superheating the admixtl and returning it to the zone of combustii In testimony whereof, I have hereunto my hand and ailixed my seal in the presei of the two subscribing Witnesses.

FREDERICK L. MCGAHAN. [11. S.

Witnesses:

EDGAR W. JAooBs, W. A. ALEXANDER. 

